Circular disk media devices rotate at a constant angular velocity while accessing the media. Therefore, a read/write rate to and from the media depends on the particular track being accessing. Access rates conventionally increase as distance increases from a center of rotation for the media. Referring to FIG. 1, a block diagram illustrating a conventional mapping for a redundant array of inexpensive disks (RAID) level 1 system is shown. The RAID 1 system is commonly viewed by software as a virtual disk 10 having multiple contiguous logical block addresses (LBA). Each virtual LBA may be stored on a data drive 12 at a physical LBA. Each physical LBA may also be mirrored to and stored in a parity drive 14. Therefore, each virtual LBA is stored at the same physical LBA location in both the data drive 12 and the parity drive 14.
The RAID 1 system can be implemented with more than two disk drives. An equal number of data drives 12 and parity drives 14 will exist for the RAID 1 virtual disk 10 with each of the parity drives 14 containing a mirror image of a data drive 12. Furthermore, access time to the virtual disk 10 will increase as a position of the LBA number moves closer (i.e., increases) to the axis of rotation for the disk drive media. In the LBA mapping scheme illustrated, a random read performance of the RAID 1 virtual disk 10 matches that of either single disk 12 or 14.